Wicket gate end seal for hydraulic machine

ABSTRACT

A piston seal is slidably contained in a slot provided in the ends of the wicket gates. Means are provided to urge this piston seal into liquid sealing engagement with the adjacent hydraulic turbine stationary components. These means are preferably in the form of pressurized hydraulic fluid directed to the chamber behind the piston seal.

United States Patent Inventor Howard A. Mayo, Jr. York, Pa.

Appl. No. 869,038

Filed Oct. 24, 1969 Patented Aug. 24, 1971 Assignee Allis-ChalmersManufacturing Company Milwaukee, Wis.

WICKET GATE END SEAL FOR HYDRAULIC MACHINE 1 Claim, 3 Drawing Figs.

US. Cl 415/163, 415/216 Int. Cl F0ld 17/12 Field ofSearch ..4l5/l48l65.

[56] References Cited UNITED STATES PATENTS 2,776,107 l/l957 Willi415/164 3,101,926 8/1963 Weber 415/164 FOREIGN PATENTS 10,710/42 9/1942Japan 415/163 88,257 1/1937 Sweden 415/160 1,317,759 1/1963 France415/151 Primary Examiner-Henry F. Raduazo Attorneys-John P. Hines,Robert B. Benson and Arthur M.

Streich ABSTRACT: A piston seal is slidably contained in a slot providedin the ends of the wicket gates. Means are provided to urge this pistonseal into liquid sealing engagement with the adjacent hydraulic turbinestationary components. These means are preferably in the form ofpressurized hydraulic fluid directed to the chamber behind the pistonseal.

WICKET GATE END SEAL FOR HYDRAULIC MACHINE This invention pertains ingeneral to wicket gates for hydraulic turbines and more particularly toa means for providing a seal between the end surfaces of the wicketgates and the turbine head cover and bottom ring.

In hydraulic turbines, it is the usual practice to utilize an annularseries of movable wicket gates cooperating with the stationary headcover and bottom ring located at the ends of the gates to control theadmission of water to the hydraulic turbine runner. The successivewicket gates of the series are ordinarily pivotally adjustable aboutparallel axes and a slight clearance is usually provided between theends of each gate andthe adjacent stationary surfaces. When the gatesare in closed position, the adjacent gates coact with each other to shutoff the major portion of the water flow. However, the working clearancesat the ends of the gates allow considerable water to leak from thesupply into the runner chamber.

' Seals have been provided between the stationary surfaces and the endsof the wicket gates in an effort to control this leakage. However, aspressures have increased, more efficient sealing has become necessary;and it is the main object of this invention to provide an improved sealbetween the stationary surfaces and the ends of the wicket gates.

A further object of the subject invention is to provide a seal meansbetween the turbine stationary components and the ends of the wicketgates which includes a piston seal slidably contained in either thestationary component or wicket gate and which is urged by pressurizedhydraulic fluid into sealing engagement with the opposite member.

A further object of the subject invention is to provide a wicket gateend seal wherein a piston seal is slidably contained in a slot in theend of the wicket gates and is urged into sealing engagement with thestationary water passageway surfaces of the turbine head cover andbottom ring.

These and other objects of the subject invention will become more fullyapparent as the following description is read in light of the attacheddrawing wherein:

FIG. 1 is a fragmentary horizontal sectional view showing I two wicketgates in the open position;

. bine generally designated 7. The wicket gates are pivotally supportedat one or both ends to the concrete foundation by means of trunnions 8and define an annulus about the turbine runner (not shown). Each wicketgate has a general air foil configuration having a leading edge 9 and atrailing edge 11. When in the closed position the leading edge of onewicket gate contacts the trailing edge of the adjacent wicket gate ef-.

fecting a seal along the contacting vertical surfaces.

Annularstationary components 12, herein shown as sideplates, areprovidedin the concrete foundation adjacent opposite ends of the wicketgates. In the preferred embodiment of this invention as best shown inFIG. 2, a stepped shoulder 13 is provided at each end of each wicketgate. A plate 14 is rigidly connected to the ends of wicket gates by anyconventional means such as screws 16 covering the laterally open end ofthe shoulder. This plate 14 and the shoulder 13 define a slot 17 in theend of each wicket gate. A piston seal 18 is slidably contained in eachslot. The seal is preferably constructed of a metallic substance such asstainless steel and extends from the trailing edge 11 around the leadingedge 9 beyond the point of vertical contact between adjacent gates. Thepiston seal and the walls of the slot 17 define a pressure fluid chamber19 therebetween. It should be understood that if a trunnion is notemployed at both gate ends, the slot 17 would preferably be machined inthe gate end surface. A pressure fluid supply pipe or conduit 21 isconnected to a passageway provided in the wicket gate trunnions 8. Thispassageway 22 is connected in fluid communication with the pressurefluid chamber 19. Pressurized fluid can then be provided through theconduit 21 into the chamber 19 to urge the piston seal l8 into liquidsealing engagement with the sideplates 12. Because the trunnions passthrough the sideplates when the wicket gates are rotated, a portion ofthe piston seal will be always engaged with the sideplates to ensurethat the piston seal does not slip out of the slot 17.

With this arrangement, is a very effective and complete seal can beprovided between the ends of the wicket gates and the sideplates.Because the seals are in the wicket gates themselves rather than in thesideplates the seals are not exposed to abrasive material that flowsover the sideplates when the gates are open. Also, with the seals in thegates rather than the sideplates, smaller pieces are machined andassembled thereby simplifying these operations. Furthermore, with thepreferred embodiment disclosed, the seals can be applied to existingunits without requiring the machining of major components of the turbinewhich may not in some instances be thick enough to accommodate theseals.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In combination with a hydraulic machine including a plurality ofwicket gates having at least one trunnion pivotally supported instationary machine components located adjacent to opposite ends of thegates, means providing a liquid seal between said stationary componentsand said gate ends comprising: walls defining a groove in at least oneend of said gates from the leading to trailing edge thereof, said groovebeing open to the end and one face of said gates; a plate releasablyconnected to the face of said gates and overlying said groove,

- said plate and the walls of said groove defining a fluid chamberhaving one open end overlying the adjacent stationary component when thegates are in a closed position; said means including a seal pistonslidably contained within said chamber and replacable when said plate isremoved; and fluid conduit means in fluid communication with saidchamber to direct pressure fluid thereto for urging said piston sealinto liquid sealing engagement with one of the stationary components.

1. In combination with a hydraulic machine including a plurality ofwicket gates having at least one trunnion pivotally supported instationary machine components located adjacent to opposite ends of thegates, means providing a liquid seal between said stationary componentsand said gate ends comprising: walls defining a groove in at least oneend of said gates from the leading to trailing edge thereof, said groovebeing open to the end and one face of said gates; a plate releasablyconnected to the face of said gates and overlying said groove, saidplate and the walls of said groove defining a fluid chamber having oneopen end overlying the adjacent stationary component when the gates arein a closed position; said means including a seal piston slidablycontained within said chamber and replacable when said plate is removed;and fluid conduit means in fluid communication with said chamber todirect pressure fluid thereto for urging said piston seal into liquidsealing engagement with one of the stationary components.